<?php

declare(strict_types=1);

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer;

/**
 * This class replaces preg_* functions to better handling UTF8 strings,
 * ensuring no matter "u" modifier is present or absent subject will be handled correctly.
 *
 * @author Kuba Werłos <werlos@gmail.com>
 *
 * @internal
 */
final class Preg
{
    /**
     * @param array<array-key, mixed>                               $matches
     * @param int-mask<PREG_OFFSET_CAPTURE, PREG_UNMATCHED_AS_NULL> $flags
     *
     * @param-out ($flags is PREG_OFFSET_CAPTURE
     *     ? array<array-key, array{string, 0|positive-int}|array{'', -1}>
     *     : ($flags is PREG_UNMATCHED_AS_NULL
     *         ? array<array-key, string|null>
     *         : ($flags is int-mask<PREG_OFFSET_CAPTURE, PREG_UNMATCHED_AS_NULL>&768
     *             ? array<array-key, array{string, 0|positive-int}|array{null, -1}>
     *             : array<array-key, string>
     *         )
     *     )
     * ) $matches
     *
     * @throws PregException
     */
    public static function match(string $pattern, string $subject, ?array &$matches = null, int $flags = 0, int $offset = 0): bool
    {
        $result = @preg_match(self::addUtf8Modifier($pattern), $subject, $matches, $flags, $offset);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return 1 === $result;
        }

        $result = @preg_match(self::removeUtf8Modifier($pattern), $subject, $matches, $flags, $offset);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return 1 === $result;
        }

        throw self::newPregException(preg_last_error(), preg_last_error_msg(), __METHOD__, $pattern);
    }

    /**
     * @param array<array-key, mixed>                                                                   $matches
     * @param int-mask<PREG_PATTERN_ORDER, PREG_SET_ORDER, PREG_OFFSET_CAPTURE, PREG_UNMATCHED_AS_NULL> $flags
     *
     * @param-out ($flags is PREG_PATTERN_ORDER
     *     ? array<list<string>>
     *     : ($flags is PREG_SET_ORDER
     *         ? list<array<string>>
     *         : ($flags is int-mask<PREG_PATTERN_ORDER, PREG_OFFSET_CAPTURE>&(256|257)
     *             ? array<list<array{string, int}>>
     *             : ($flags is int-mask<PREG_SET_ORDER, PREG_OFFSET_CAPTURE>&258
     *                 ? list<array<array{string, int}>>
     *                 : ($flags is int-mask<PREG_PATTERN_ORDER, PREG_UNMATCHED_AS_NULL>&(512|513)
     *                     ? array<list<?string>>
     *                     : ($flags is int-mask<PREG_SET_ORDER, PREG_UNMATCHED_AS_NULL>&514
     *                         ? list<array<?string>>
     *                         : ($flags is int-mask<PREG_SET_ORDER, PREG_OFFSET_CAPTURE, PREG_UNMATCHED_AS_NULL>&770
     *                             ? list<array<array{?string, int}>>
     *                             : ($flags is 0 ? array<list<string>> : array<mixed>)
     *                         )
     *                     )
     *                 )
     *             )
     *         )
     *     )
     * ) $matches
     *
     * @throws PregException
     */
    public static function matchAll(string $pattern, string $subject, ?array &$matches = null, int $flags = PREG_PATTERN_ORDER, int $offset = 0): int
    {
        $result = @preg_match_all(self::addUtf8Modifier($pattern), $subject, $matches, $flags, $offset);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        $result = @preg_match_all(self::removeUtf8Modifier($pattern), $subject, $matches, $flags, $offset);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        throw self::newPregException(preg_last_error(), preg_last_error_msg(), __METHOD__, $pattern);
    }

    /**
     * @param array<array-key, string>|string $subject
     *
     * @param-out int $count
     *
     * @throws PregException
     */
    public static function replace(string $pattern, string $replacement, $subject, int $limit = -1, ?int &$count = null): string
    {
        $result = @preg_replace(self::addUtf8Modifier($pattern), $replacement, $subject, $limit, $count);
        if (null !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        $result = @preg_replace(self::removeUtf8Modifier($pattern), $replacement, $subject, $limit, $count);
        if (null !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        throw self::newPregException(preg_last_error(), preg_last_error_msg(), __METHOD__, $pattern);
    }

    /**
     * @param-out int $count
     *
     * @throws PregException
     */
    public static function replaceCallback(string $pattern, callable $callback, string $subject, int $limit = -1, ?int &$count = null): string
    {
        $result = @preg_replace_callback(self::addUtf8Modifier($pattern), $callback, $subject, $limit, $count);
        if (null !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        $result = @preg_replace_callback(self::removeUtf8Modifier($pattern), $callback, $subject, $limit, $count);
        if (null !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        throw self::newPregException(preg_last_error(), preg_last_error_msg(), __METHOD__, $pattern);
    }

    /**
     * @return list<string>
     *
     * @throws PregException
     */
    public static function split(string $pattern, string $subject, int $limit = -1, int $flags = 0): array
    {
        $result = @preg_split(self::addUtf8Modifier($pattern), $subject, $limit, $flags);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        $result = @preg_split(self::removeUtf8Modifier($pattern), $subject, $limit, $flags);
        if (false !== $result && PREG_NO_ERROR === preg_last_error()) {
            return $result;
        }

        throw self::newPregException(preg_last_error(), preg_last_error_msg(), __METHOD__, $pattern);
    }

    private static function addUtf8Modifier(string $pattern): string
    {
        return $pattern.'u';
    }

    private static function removeUtf8Modifier(string $pattern): string
    {
        if ('' === $pattern) {
            return '';
        }

        $delimiter = $pattern[0];

        $endDelimiterPosition = strrpos($pattern, $delimiter);

        return substr($pattern, 0, $endDelimiterPosition).str_replace('u', '', substr($pattern, $endDelimiterPosition));
    }

    /**
     * Create the generic PregException message and tell more about such kind of error in the message.
     */
    private static function newPregException(int $error, string $errorMsg, string $method, string $pattern): PregException
    {
        $result = null;
        $errorMessage = null;

        try {
            $result = ExecutorWithoutErrorHandler::execute(static fn () => preg_match($pattern, ''));
        } catch (ExecutorWithoutErrorHandlerException $e) {
            $result = false;
            $errorMessage = $e->getMessage();
        }

        if (false !== $result) {
            return new PregException(sprintf('Unknown error occurred when calling %s: %s.', $method, $errorMsg), $error);
        }

        $code = preg_last_error();

        $message = sprintf(
            '(code: %d) %s',
            $code,
            preg_replace('~preg_[a-z_]+[()]{2}: ~', '', $errorMessage)
        );

        return new PregException(
            sprintf('%s(): Invalid PCRE pattern "%s": %s (version: %s)', $method, $pattern, $message, PCRE_VERSION),
            $code
        );
    }
}
